IKs, a slow and intriguing cardiac K+ channel and its associated long QT diseases

Shaping of cardiac action potentials depends on a finely tuned orchestra of ion channels. Among them, K+ channels probably form the most diverse family. They are responsible for inwardly rectifying (1(K1), I-KAch, I-KATP), transient (I-to), and sustained outward rectifying (I-Kur, I-Kr, I-Ks) K+ currents. The properties of these cardiac K+ channels have recently been extensively reviewed. This article focuses on recent progress made toward understanding the molecular structure of the particular channel responsible for the slow outward K+ current I-Ks and its implication in the delayed ventricular repolarization that characterizes the congenital long QT syndrome. (C) 1998, Elsevier Science Inc.